1. Field of the Invention
The present invention relates to water purification, and particularly to treatment media for removing microscopic contaminants from water. More particularly, the present invention provides treatment media for incorporation within techniques and equipment that treat drinking water, and/or water present in pools, spas and the like with activated silver ions in order to render such water substantially free from germs, bacteria and microbes, and to residually prevent or deter the formation of such undesirable, potentially harmful contaminants for a non-nominal time following treatment of the water.
2. Description of Related Art
For many years, people of all ages have enjoyed the health benefits of consuming drinking water (e.g., tap water or well water), as well as the recreational and/or therapeutic effects of swimming, wading or simply placing themselves within water containment units (e.g., pools, soaking tubs, jacuzzis, whirlpool baths, water spas).
Over time, however, it has become known that both tap and well water, whether due to contamination of the water supply and/or of the (e.g., pipes, buckets) that transport water from the water supply to its consumers, often contain harmful bacteria, microbes, viruses, parasites, protozoa, and/or other harmful elements (collectively xe2x80x9cgermsxe2x80x9d). And more recently, people have been alerted to the fact that water contained in pools, tubs and other similar units, if left untreated, will likewise develop the same types of germs, which can be just as harmful through prolonged (or even short term) physical contact therewith.
In reaction to such knowledge, those who oversee pools, spas and like units, or are responsible for their upkeep have taken steps to ensure that water in such units is substantially germ free. Similarly, many individuals began to treat their tap/well water prior to drinking it in hopes of eliminating germs contained therein. Unfortunately, due to problems with and/or limitations of many existing treatment methods, such efforts either are entirely ineffective to eliminate germs, or are only able to do so for short periods of time in manners wherein costly, time-consuming, and/or harmful side effects likely occur.
Currently, in-home treatment of drinking water usually consists of routing it through a rudimentary filtration unit. The majority of such units are not ideal, however, because although they are generally effective to remove some dirt, sediment and metals (e.g., lead, arsenic) from within water, they are incapable of removing germs therefrom. In fact, if a filtration unit isn""t properly maintained (i.e., cleaned or replaced) within a limited time frame (i.e., from several weeks to a few months), germs could begin to form within the filter, and, in turn, could be transmitted to the water that passes through the filter.
At present, treatment of water that fills pools, spas and the like usually consists of the introduction of one or more chemicals into the water at predetermined time intervals. Such chemicals (chlorine is the most popular), if introduced in correct amounts, usually are effective to remove germs that are present within the water in these environments. Many problems, however, are associated with the use of such chemicals (especially chlorine) for this purpose.
For example, chlorine has a distinctive smell that many find unpleasant, and some even describe as overwhelming. Also, people may suffer a panoply of undesirable physical reactions (e.g., skin irritation and/or itchiness, redness and/or irritation of the eyes, negative effects on hair) upon exposure to chlorine. Further, chlorine tends to cause coloring in fabrics (i.e., bathing suits) to fade significantly if the fabrics are not thoroughly rinsed immediately upon exiting the chlorine-treated environment.
Moreover, those who are actually entrusted with adding chlorine to water are more susceptible to these risks because they encounter the chlorine in a non- or less diluted state. As such, they must exercise added care not to inhale its fumes or to allow it to contact their eyes/skin/hair. Perhaps even more importantly, they must also ensure that certain substances (e.g., other types of chlorine, certain algaecides, alkalis and acids, and even certain types of dirt and debris) do not come into contact with the chlorine prior to its dilution in order to avoid the risk of spontaneous combustion.
An additional problem linked to treating water in pools, spas or like units with chlorine is that, over time, objects (e.g., pool covers/liners, furniture) placed on, or located near such pools, spas or like units are caused to prematurely degradexe2x80x94thus being rendered unsightly and/or physically unstablexe2x80x94due to their exposure to chlorine and/or its fumes.
Still other drawbacks of using chlorine to treat water relate to the natural effects of the outdoors. Because chlorine is a relatively volatile gas, it is rapidly dissipated from water in open atmospheres, which, unfortunately, is where pools, spas, and like units often are located. This dissipation is expedited in water that is brought to temperatures above 70xc2x0 F. (and, in particular, above 85xc2x0 F.), which is a temperature level that many such water units routinely reach.
Yet one cannot simply address this problem by adding more chlorine to the water when one is in doubt as to whether chlorine is needed because that would cause most, if not all of the above-indicated problems to be more prevalent and/or their effects to be magnified/heightened.
Many water treatment methods (e.g., use of magnets, oxygen generators, ozone generators, and/or ultraviolet devices) have been proposed as alternatives to those described above, but have been largely dismissed as being too costly, non-efficacious, and/or as incompatible with small-scale use (e.g., use by individual home owners to treat drinking water and/or a pool).
One treatment approach that has met with success and acceptance, however, involves the use of heavy metalsxe2x80x94in particular, those of the type commonly referred to as xe2x80x9coligodynamic metalsxe2x80x9dxe2x80x94to eliminate germs from water.
Oligodynamic metals, especially silver ions, have a germicidal effect when present in water, even at concentration levels as low as 10 parts per billion. As a result, they can be effectively utilized to maintain germ levels in water well within tolerable ranges that permit the safe use of water both for drinking purposes and for short term or prolonged contact with the body (i.e., in pools, spas or like units).
The principal benefits of oligodynamic metal ion water treatment methods are that they are highly efficacious, are not unduly expensive or time consuming, and, arguably most importantly, their use does not present the above-indicated problems that plague use of chlorine and other chemicals.
Several patents (U.S. Pat. Nos.: 4,504,387, 4,608,247, 4,935,116, and 5,478,467) are directed to techniques and equipment for purifying water via oligodynamic metal ion treatment (e.g., silver catalysis). And while the techniques and equipment described therein represent significant improvements in terms of safety and effectiveness as compared to conventional treatment methods (e.g., drinking water filtration and use of chlorine to treat pool and spa water), there is room for improvement thereto, especially with respect to the ability of such techniques to provide residual, germicidal treatment to the water.
Therefore, an object of the present invention is to provide metal (e.g., silver) ion-based water treatment media and techniques that avoid the drawbacks of conventional alternatives, yet retain the beneficial aspects of known metal ion treatment techniques and equipment, while rendering such techniques and equipment even more effective, especially with respect to providing improved residual, germicidal treatment of water.
A related object of the present invention is to ensure that such media and techniques are rendered more effective without a noticeable increase in cost and/or in the duration/complexity thereof.
Another related object of the present invention is to ensure that such media and techniques are particularly more effective when used to treat well and/or tap water that is to be stored for non-nominal time periods prior to being consumed, and when used to treat non-filtered pools, spas and like units.
The present invention is directed to a treatment media for purifying water, and methods for forming such treatment media. In an exemplary aspect of this invention, the treatment media is provided as an alumina substrate of predetermined weight that has been heated to a temperature in the range of 375xc2x0 F. to 300xc2x0 F. A quantity of silver ions have been deposited on the alumina substrate in an amount such that the weight of the quantity of silver is in the range of about 1% to 10% of the predetermined weight of the alumina substrate.
Use of such a treatment medium to treat water results in improved (as compared to known conventional and specialized techniques and equipment) silver ion release and catalysis reactions such that the level of germs present within the water treated by the treatment medium, both immediately and residually following treatment, will be within tolerable levels, thus rendering such water suitable for drinking or for placement within a pool, spa or like unit.
In a related aspect of the invention, activated charcoal is introduced within the alumina as a filler material. The presence of the filler material is beneficial because of it is substantially softer than silver, and because it has excellent absorption properties. Generally, the filler material is intermixed within the alumina such that the weight ratio of activated charcoal to alumina is in the range of about 5:1 to 1:1, preferably about 2:1.
In order to ideally support the silver ions deposited thereupon, the alumina substrate should have a particle size in the range of about 4 mesh to 20 mesh (preferably in the range of about 8 mesh to 14 mesh), and a porosity that provides a surface area of greater than about 150 in2/gram (preferably about 210 in2/gram). The alumina substrate also should have a Mohs scale hardness greater than the hardness of silver, which has a Mohs hardness of about 2.5. Preferably, the alumina substrate has a Mohs scale hardness that is greater than about 9.0. Further, the alumina substrate should be substantially insoluble in water, and should have a pH within the range of about 5 to 9.
When included, the activated charcoal filler material should have a particle size in the range of approximately 4 mesh to 20 mesh, wherein its particle size is preferably substantially the same as that of the alumina substrate. Also, like the alumina substrate, the activated charcoal should be substantially insoluble in water, and should have a pH in the range of approximately 5 to 9. Unlike the alumina substrate, however, the activated charcoal should have a hardness less than the hardness of silver (i.e., less than about 2.5) according to the Mohs scale.
In embodiments in which filler material is intermixed within the carrier material, the weight and/or volumetric ratio of filler material to carrier material generally is in the range of about 5:1 to 1:1, preferably about 2:1.
Still other aspects and embodiments of the present invention are discussed in detail below.